The present invention relates to hinge pins used as bushings to pivotally connect two members together, and more particularly to a novel two-piece hinge pin which, when assembled, defines a cylindrical sleeve. The cylindrical sleeve includes two sections which are slidable with respect to each other so that the pin may be readily removed from within a rubber mounting.
In heavily loaded vehicles, it is known to provide walking beams which are pivotally-connected to U-shaped axle brackets. An axle is situated on top of the bracket. Because of the heavy loading, a cylindrical sleeve serving as a hinge pin is disposed within a rubber mount which in turn is fitted within a bore of the walking beam. The cylindrical sleeve serves as a hinge pin connecting the axle bracket to the walking beam. A bolt is inserted through the pin and includes washers at the ends in order to keep the sleeve from working its way free.
A problem resulting from the above construction resides in the fact that the cylindrical sleeve may become damaged or scored due to heat and the heavy loading. Such distortion requires that the entire bushing be periodically replaced, a task somewhat difficult and burdensome as well as time consuming because the inner cylindrical sleeve may not be readily removable because of its distorted condition. Consequently, in order to remove such a sleeve, it is necessary that they be secured to a wheel puller or be physically knocked out of engagement with the outer resilient bushing.
Prior art hinge pin bushings generally take the form of an outer cylindrical rubber sleeve which is inserted in a circular bore in a member to be pivotally connected to another member. Circumferentially disposed within the inner diameter of the rubber sleeve is a cylindrical metal sleeve which serves as a bearing surface for a bolt interconnecting the two members together. It has been proposed to taper a hinge pin so that it has a generally cup-shaped collar movable into a wedged position in a surrounding bore as disclosed in U.S. Pat. No. 3,841,771. A larger bolt may then be advanced to move a collar out of wedged engagement for facilitating removal. However, while removal from a collar may be facilitated, there is no provision for the ready removal of the inner metal sleeve of a bushing from the main bore through which the bushing is inserted.
In U.S. Pat. No. 3,600,789, there is disclosed an anchor which has a conical or tapered cross-section employed as a wedge within a tubular outer member for securing a drive bolt within a wall. If the anchor is displaced outwardly, it would slide readily from the tubular member if the bolt were removed because of the tapered feature of the anchor. However, such a construction does not appear to be applicable for use as a cylindrical metal sleeve within a rubber mounting.
While not directly applicable to bushings or bearings, U.S. Pat. No. 647,020 disposes an adjustable key having two tapering parts which are used to compensate for the lengthening or shortening of a piston rod within a cylinder. While the adjustable key has tapering portions, it is to be noted that the key is solid and could not be readily adapted for use as a sleeve member.